Cracked corner casting...issues

Cracked my right rear corner casting. Scored a replacement of unknown vintage. All was good till I went to put the pylon bolt in. Hole is not even close. Guess these are just drilled as the boat is assembled rather than jigged up?
So do I go ahead and re-drill through the pylon? Drill a whole new hole through casting and pylon? Tig up the hole in the pylon and re-drill?
Any other options I am not seeing??
FYI...the boat was making all kinds of noise and seemed to be a lil more flexy than I remembered before I noticed the crack. We were sailing in big wind double trapped for days on end with it cracked I think lol.

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1980 H16

Options that I can think of....

1) Buy a new corner casting and be done with it.
2) Drill through the pylon to match the hole in your replacement casting and then epoxy and bolt the corner casting in place.
3) Drill a new bolt hole through the casting and pylon above the existing hole(s).
4) Fill and re-drill the hole in the pylon. There was a hotline article not to long ago that described how to do this with brazing material that works using a propane torch.

sm

Are new corner castings un drilled?
Curious how #1 could fix issue?

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1980 H16

Good point. That was my assumption based on the fact that that the hole locations are different from one casting to another. You would definitely want to verify from a dealer that the pylon is undrilled before forking out the $$$ for one though.

By the way, the pylon repair article was in the Mar/Apr 2010 Hotline issue.

sm

Checked that article out...interesting. I want to pick up some of that aluminum rod they were using just to have around.
I just priced new castings $200 a pop. OUCH. Not going that route. Also noted that every pic of new castings I found online had the holes drilled for the pylon bolts already. And called up a dealer and asked and as far as they knew they come pre-drilled.


So I think I am going to just wallow out the holes enough to get a bolt through. And sail it. If its flexy I will think about gluing it but that sounds like a real pain if I should ever need to get the frame apart again. Some of the joints were hard enough without glue!

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1980 H16

Having replaced my hulls i delt with the same issue, I just drilled overlapping holes in the plylons to allow the bolts to pass through. As far as epoxing the frame and hulls togeather, night a day difference between unglued. it was so much easier to fly a hull and tack and lost alot less speed in waves and chop. I have also dissasembled a boat that had been epoxied togeather, and it was easy to get apart, a few taps with a mallot and while applying heat with a blowtorch (the epoxy i used melts at 140 degrees F) and it poped right off. I have actualy had more trouble taking appart and old boat for the first time than i did taking apart a boat that was epoxied togeather. i used west Systems with 404 high density filler

Would you like to try a different casting?

I have had a 1981 H16 Frame (good shape) that I cannot bear to give to the junkman, but I need to part it out. I can pull the casting and send it to you if you like (Free of course).

If anyone else needs corner castings, let me know.

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1980 18 foot class A Unicorn catamaran
1977 Super Sunfish (sold)
1979 Hobie (sold)
1983 Hobie 16 Hawiian Sunset (sold)
1981 Hobie 16 Tequilla Sunrise (sold)
2008 Hobie 16 (sold)
2023 Hobie 16
Founding member of the "San Dimas Yacht Club"
John

Thanks for the offer. I went ahead and drilled the pylon to fit. Boat is tight and sails great. Don't toss your spares! Someone will need them!

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1980 H16

Hey . new member here . trying to see if welding or expoxy of some sort would work to repair cracked corner casting or is that ill advised? thanks.

Not something I have heard work.

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Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

We fix casting cracks somewhat frequently here in the shop. You MUST drill a hole at the end of the crack to prevent it from continuing to split later down the road. Grind a "V" at the crack so the filler has a place to go and a lot of surface area to fuse to. Do the inside of the casting as well if the welder can get into it, ensuring plenty of penetration from both sides. Clean the area good enough to lick, preheat (I believe we do 400*) right before it's welded back up. Grind the excess weld enough for the crossbar to fit in. If you do all of this there is a good chance it will not split any more. It is still a gamble being a high stress part, but I've never heard a customer come back that has had their casting break after we weld it this way, some of those parts have been under a lot of stress. Most places do not know how to stop the split with drilling out at the end of the crack, and some welding shops don't even know that cast aluminum needs preheated, so make sure you verify the process they use to weld it. I'd say it's worth a shot. I had a tiller bar split 1/2 way down it and still holding up after over a year.

**edit**
Just want to note that I'm not trying to dismiss Matt's comment, I'm just saying if prepared and welded properly, there is a good chance it will hold up.

I ran into a similar issue when rebuilding my 1978 H16. I had to replace the front left corner casting due to it being cracked where it goes over the pylon. Since the hole didn’t line up, I removed some of the foam core in the pylon to about 2” below the existing bolt hole. I then filled the pylon with epoxy (being careful not to plug the vent tube). Then I put the new corner casting in place and drilled the pylon to fit my new corner casting. I don’t know if that’s the right way to do it, but it worked for me. Good luck.

thanks!